Get to know your orchid medium, what types exist and how to use them.
Potting orchids with different types of medium.
If you happen to be a novice to the orchid world and have never owned one before, it can be confusing to know which potting medium is best for your orchid. The main difference between orchids and other household plants is that 70% of all orchids are Epiphytes. Epiphytes (air plant) usually cling on to surfaces of trees, other plants and rock. If you plant an orchid in dirt, it will likely die as it is not getting sufficient airflow to the roots.
There are lots of options, so let's have a look at the different types of potting mediums that can be used for your orchids.
Bark
Bark is a natural material that looks and feels authentic and it's great for use in terrariums. Fir or Pine bark are some of the most commonly used. The chunky nature of the bark makes it fantastic for aerating, resisting compaction and providing drainage in a substrate mix. It also soaks up water and increases water retention to a certain degree, helping to boost ambient humidity. When used as a substrate, orchid bark will break down and acidify over time. If you’re looking for a longer lasting option, try coco fiber instead. Bark is available in different size grades, so pick one to your needs- we will explore this later down the page.
Fine Grade Orchid Bark
If you are creating your own orchid mix and need some orchid bark to make up a portion of it, we believe that this is your best bet. It’s also better for younger or smaller plants in general. A finer mix of bark and other mediums is usually a good option for orchids with smaller and finer roots to have more water retention and increase the humidity.
Medium Grade and Coarse Orchid Bark
A larger grade bark will drain and dry very quickly. They work best when you want orchid bark to be the main part of a mix, rather than just one of the ingredients. Mostly Epiphytes like Bromeliads and larger rooted orchids will grow well in a super chunky, well aerated mix.
Sphagnum Moss
Sphagnum moss comes in many shapes and forms, long & short as well as in the form of fine petals. Often sourced by harvesting from bogs, we know that Sphagnum moss is the most ideal for moisture loving orchids. We suggest using excellent quality long fibered AAA New Zealand Sphagnum moss as it can be used alone or even mixed with other potting media. In addition, this material can be used as an effective top dressing as it increases humidity around the plant while also being an excellent base to use if you choose to mount your orchids as it holds water very well especially if packed tightly together.
Perlite
Perlite, often known as sponge rock is a common ingredient in orchid mixes as it decreases compaction of the mix, increases aeration while retaining moisture and improving drainage. Sponge rock is a volcanic glass that expands when heated and becomes highly porous, making it a wonderful material for germination, seedling and peat mixes.
Charcoal
Charcoal is often added to orchid mix with the intention of filtering impurities and keeping the mix sweet. Alternatively, charcoal can be used on its own or mixed with other potting materials depending upon the type of orchid. The charcoals particle size which is usually around 0.5-2 inches is ideal for the majority of orchid mixes for seedlings and fine rooted orchids. We believe that charcoal is the perfect medium for growing orchids as it aids drainage and allows air through to the plants roots. Most potting materials for orchids do not provide any nutrients and so fertilisers are added, yet charcoal assists in storing those nutrients aiding fertility whilst absorbing minerals and salts that may harm the plants roots.
Hydroton Clay Pebbles
It is a lightweight expanded aggregate which is similar to Aliflor, Hydrokorrel, Hydrocks, Leca stone among other materials. Being economically sustainable, it is derived from clay which is a widely available source. Orchids love clay due to its porosity as roots can be easily wrapped around it. Advantages of this material include its free draining properties, pH neutrality and can easily expand similarly to popcorn, making it very porous. Additionally, its uneven shape and size provides good root support. If that wasn't enough, Hydroton is dust free and facilitates good oxygen levels at the root zone.
Coconut Husk Chips
Being a popular alternative to Fir bark, coconut husk chips are pretty easy to water and break down slower in comparison to bark as they remain open and airy for longer periods. This material mixes well with other ingredients in order to create a wide variety of orchid mixes as it absorbs water well and holds onto it like a sponge, releasing water when the roots require it. We find this material easy to work with and are a well known renewable resource.
These are just some of the major mediums in use, while more specific mediums like coconut fiber, cork and rockwool are available in a variety of size grades, while one mix doesn't have to fit all your orchids, you should be able to create a suitable orchid mix with the above examples and keep your orchids happy.